B. it allowed humans to continue to treat everyone in society equally
During World War II, many men were gone fighting in the war. This meant that women had to take jobs that were traditionally occupied by men. Women, as it turns out, as just as smart as men (sarcasm) and women realized that staying home wasn't their only option.
When writing an essay like this, I would devote one paragraph to talking about how supply and demand dictate prices, and another paragraph to how international trade fuels economic growth.
The Helots were state-owned serfs of the ancient Spartans.